ballast tank and freezing temperatures

ericorville · Post by **ericorville** » Thu Nov 04, 2004 8:00 am

When the temperatures fall I notice that it is almost impossible to get the last bit of water out of the ballast tank. I am also concerned that there are cavities that may not drain on either side of the centre board trunk. I would like to see a CAD drawing (or other engineering drawing) of the ballast tank structure. Also, does anyone use a recreational vehicle pumbing anitfreeze to deal with this problem?
Eric

Chip Hindes · Post by **Chip Hindes** » Thu Nov 04, 2004 9:07 am

Many of us live in locations where, if this were a problem, we would certainly have seen it. What leads you to think this could be a problem?

Randy Smith · Post by **Randy Smith** » Thu Nov 04, 2004 11:38 am

Living in the Northwest and not usually taking my boat out(because there is nothing better than a snowing, blustery day, curled up on the birth watching a movie, and to make it even better, playing hooky from work...Gawd sometimes I even READ!) I have worried about the water ballast.....I sometimes pay extra at the dock for electricity to run a portable heater...Ranger will goof and pull plug sometimes(idiot)..he sunk a Caver last year 160,000 clams. I have put in environmentally friendly anti freeze....but it takes alot to treat 350 gallons

...I have decided I will take the boat home Thanksgiving, though I do not want to!!! Maybe, I can cheat to Christmas(you can see it is a delima........

)

Randy

Remember, the ballast is below the water line and it has to be very cold to freeze the water that low....last winter it was 15 below for a week, 6 inches of ice on the water...the heater was off (Ranger Dick) and there was just a slight bit of ice at the cork....the rest of the water seemed to be liquid....it did scare me, that is why I am gonna bring Breezy home sometime........

Dimitri-2000X-Tampa · Post by **Dimitri-2000X-Tampa** » Thu Nov 04, 2004 2:23 pm

Also, if you have salt water in the tank, the freezing temperature is a few degrees colder than fresh water.

Chip Hindes · Post by **Chip Hindes** » Thu Nov 04, 2004 2:46 pm

It never occured to me we may have been talking about a boat still in the water. Doesn't change the question. What's the problem? The water in the ballast tank can't freeze any sooner than that surrounding the boat, and if the water surrounding the boat freezes, you've got more problems than a little water left in the ballast tank.

Remember, the ballast is below the water line

Actually, the height of the water in the ballast tank is the height of the waterline. If it were below the waterline and you inadvertantly left the plug out, you'd sink the boat.

waltpm · Post by **waltpm** » Thu Nov 04, 2004 5:22 pm

I live in western NY and have never had any problems with an empty tank freezing. I don't even cover the boat and usually have 2-4 feet of snow and ice in the cockpit.

Randy Smith · Post by **Randy Smith** » Fri Nov 05, 2004 1:49 pm

Chip, in the 96, the plug is at waterline but the tanks are in the bottom of the boat which is below waterline right? My tank plug is under the companionway, not in the bow like later models.

Randy

Also, the ice was six inches around the boat, so solid that my 250 lbs barely broke it.....the boat, even with her chine, rode up on the ice like the good girl she is.....again, one winter of this and I figured it wasn't worth it to leave her in, but she hung tough...........

Catigale · Post by **Catigale** » Fri Nov 05, 2004 5:34 pm

I might be missing this but I think the points were:

1 If the outside isnt frozen, the ballast wont be frozen - I guess if you fresh water sailed, filled the tank, then went to a salt water port in winter you might be able to pull this off via a miracle of chemistry known as Molal Freezing Point Depression.

2 If the outside is frozen, your outer hull is in more danger than your ballast tank.

3 Oh yeah, a ballast filling valve below the waterline is also called a hull leak....

Jeff Drumm · Post by **Jeff Drumm** » Fri Nov 05, 2004 7:46 pm

I remember Bob Cardoza telling me that he wound up with a 26X whose ballast froze solid during the winter of 2002-2003 (can't quite figure out how, unless it had fresh water in the tank but was slipped/moored in salt water). No damage, and with the tank full I'd expect that to be more likely than with only a small amount of water in it.

Chip Hindes · Post by **Chip Hindes** » Fri Nov 05, 2004 8:48 pm

Chip, in the 96, the plug is at waterline but the tanks are in the bottom of the boat which is below waterline right? My tank plug is under the companionway, not in the bow like later models.

Well of course, most of the water in the ballast tank is below the waterline, otherwise, it wouldn't flow in when you opened the valve. But the vent is most definitely above the waterline unless the boat is heeled or excessively loaded. You certainly could load it heavily enough to sink the vent below the waterline, but you wouldn't want to do so.

If you slipped the boat in salt water with a ballast tank full of fresh water, the salt water could get cold enough to freeze the water in the tank without itself freezing.

You could also allow the water around the boat to freeze, at which point the ballast tank water would likely freeze as well; the water around the boat would likely thaw first, while the ballast tank remained frozen. I wouldn't make this a regular practice.

You could also pull the boat without draining the ballast (a bad idea in and of itself) and it will freeze in the ballast tank as soon as the temp's below 32 degrees.

I'm impressed with the story of the ballast tank that froze solid without damage, but 1) it took some effort to aqccomplish this feat, and 2) I would certainly not make this a common practice either.

The real point is, a little water remaining in an "empty" ballast tank is harmless.

MacGregorSailors.com

MacGregorSailors.com

ballast tank and freezing temperatures

ballast tank and freezing temperatures